html,body,p,h3{
  margin: 0;
  padding: 0;
}
body{
  color:#000;
  font: 16px/1.5 "微软雅黑", "宋体", "Arial", "sans-serif";
}
.container{
  max-width: 800px;
  min-height: 500px;
  border: 5px solid red;
  margin: 50px auto;
  padding: 0 20px;
}
.container h3{
  height: 80px;
  font-size: 36px;
  border: 1px solid #000;
  text-align: center;
  line-height: 80px;
}
.insert-product .item{
  display: flex;
  align-items: center;
  margin-bottom: 20px;
}
.insert-product .item label{
  width: 120px;
  font-size: 18px;
}
.insert-product .item input{
  flex-grow: 1;
  height: 40px;
  outline: none;
  border: 1px solid #ccc;
}
.insert-product .item input::placeholder,.insert-product .item textarea::placeholder{
  font-size: 18px;
}
.insert-product .item textarea{
  height: 100px;
  flex-grow: 1;
}
#image{
  display: none;
}
.product-image .preview{
  width: 120px;
  height: 100px;
  background: url('../image/image.png') no-repeat;
}
.product-image label.upload-btn{
  margin-left: 20px;
  width: 100px;
  height: 100px;
  border: 1px dashed #ddd;
  background-color: #fafafa;
  border-radius: 10px;
  cursor: pointer;
}
.submit button{
  display: block;
  width: 120px;
  height: 50px;
  background-color: #409eff;
  color: #fff;
  border: 1px solid #1479dd;
  border-radius: 5px;
  margin: 0 auto;
  font-size: 20px;  
}